Balances in the retail sector have a display on which the weight of a weighed article can be viewed. According to regulations in most countries, weight measuring devices must be calibrated and approved by the standardizing authorities if they are used for billing purposes.
Such balances are often used together with a cash register, the cash register registering the prices of the weighed articles together with other articles that do not have to be weighed. Both devices have displays facing the customer, so-called customer displays, to display the amount, the unit price and the respective price. If the customer is also to be given a receipt relating to the amount of the article, two receipt printers are required, one on the balance and one on the cash register. Such a combination of a balance and cash register is represented in DE 30 03 255 A1.
A single device with only one display and one receipt printer is desirable, the display and the receipt including both the weight values and the prices of the weighed articles and being able to be used to display and print out the number of items, description and price of other, non-weighed articles. A joint display is permissible if the data displayed cannot be confused with weight values or prices derived from them. Regulations on this can be found in DIN EN 45 501, which corresponds to the recommendations R 76-1 of the “Organisation Internationale de Metrologie Legale”, O1ML.
A combination of a cash register and a balance with a customer display shared by both devices has been proposed in DE 44 08 549 A1, the electronics of the balance only allowing display data that are compatible with the weighing undertaken at the particular time. The evaluation unit does not itself provide any outputs on the display unit. Rather, after reception of the weighing data from the measuring pickup, the weighing result is initially transmitted from the evaluation unit into the cash register. There, a price is determined by means of a price table and a display is compiled and sent to the evaluation unit. The evaluation unit checks the desired display texts to ascertain that they are not inadmissible and displays them.
The aforementioned combination of the cash register with a balance has the disadvantage that the evaluation unit is connected directly to the PC bus, which presupposes both special operating system software and special user software. Furthermore, customers are not accustomed to reading information concerning prices and quantities from the customer display of a balance.
WO 95/14367 A1 discloses a control device referred to as an ‘electronic box’, which is constructed on the PC principle. It contains a motherboard, the rear edge of which is provided, inter alia, with a plug for a keyboard and with connection sockets for serial and parallel peripheral interfaces. Arranged parallel to the motherboard are additional printed circuit boards, which are constructed on the basis of the PC-AT standard and, on an edge parallel to the rear edge of the motherboard, bear connection plugs for further peripheral connections. The additional printed circuit boards are connected to the motherboard by being plugged on means of a bus expansion card.
The general object of the invention is to provide a combination cash register and balance having only one customer display which manages with previously customary cash register software.